Experimental investigation ot non-linear phenomena in electron beams at fundamental and harmonic frequencies

A knowledge of the behaviour of electron beams under large signal conditions is basic to any attempt to improve the efficiency of high power klystrons, and also tb the design of frequency multipliers. The latter are of considerable interest for millimeter wave generation. It is a remarkable fact that in spite of the tremendous scale of activity in the high power klystron field, the 1iterature reveals very few experimental investigations of large signal beam modulation which are’fully quantitative. An increase of say 10% in the efficiency of a high power klystron is of great technical importance. It is clear therefore that if an experimental investigation of large signal behaviour is to make a practical contribution to the design of high power tubes, the relevant quantities must be measured with a very considerable accuracy, — of the order of a few percent. Although the need for very accurate knowledge of the harmonic content of the beam is less acute, the comparison of the results with theory represents a useful and critical test of the latter.